|Publication number||US5473701 A|
|Application number||US 08/148,750|
|Publication date||Dec 5, 1995|
|Filing date||Nov 5, 1993|
|Priority date||Nov 5, 1993|
|Also published as||CA2117931A1, CA2117931C, DE69431179D1, DE69431179T2, EP0652686A1, EP0652686B1|
|Publication number||08148750, 148750, US 5473701 A, US 5473701A, US-A-5473701, US5473701 A, US5473701A|
|Inventors||Juergen Cezanne, Gary W. Elko|
|Original Assignee||At&T Corp.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (6), Non-Patent Citations (7), Referenced by (194), Classifications (9), Legal Events (16)|
|External Links: USPTO, USPTO Assignment, Espacenet|
This invention relates to microphone arrays which employ directionality characteristics to differentiate between sources of noise and desired sound sources.
Wireless communication devices, such as cellular telephones and other personal communication devices, enjoy widespread use. Because of their portability, such devices are finding use in very noisy environments. Users of such wireless communication devices often find that unwanted noise seriously detracts from clear communication of their own speech. A person with whom the wireless system user speaks often has a difficult time hearing the user's speech over the noise.
Wireless devices are not the only communication systems exposed to unwanted noise. For example, video teleconferencing systems and multimedia computer communication systems suffer similar problems. In the cases of these systems, noise within the conference room or office in which such systems sit detract from the quality of communicated speech. Such noise may be due to electric equipment noise (e.g., cooling fan noise), conversations of others, etc.
Directional microphone arrays have been used to combat the problems of noise in communication systems. Such arrays exhibit varying sensitivity to sources of noise as a function of source angle. This varying sensitivity is referred to as a directivity pattern. Low or reduced array sensitivity at a given source angle (or range of angles) is referred to a directivity pattern null. Directional sensitivity of an array is advantageously focused on desired acoustic signals and ignores, in large part, undesirable noise signals.
While conventional directional arrays provide a desirable level of noise rejection, they may be of limited usefulness in situations where noise sources move in relation to the array.
The present invention provides a technique for adaptively adjusting the directivity of a microphone array to reduce (for example, to minimize) the sensitivity of the array to background noise.
In accordance with the present invention, the signal-to-noise ratio of a microphone array is enhanced by orienting a null of a directivity pattern of the array in such a way as to reduce microphone array output signal level. Null orientation is constrained to a predetermined region of space adjacent to the array. Advantageously, the predetermined region of space is a region from which undesired acoustic energy is expected to impinge upon the array. Directivity pattern (and thus null) orientation is adjustable based on one or more parameters. These one or more parameters are evaluated under the constraint to realize the desired orientation. The output signals of one or more microphones of the array are modified based on these to evaluated parameters and the modified output signals are used in forming an array output signal.
An illustrative embodiment of the invention includes an array having a plurality of microphones. The directivity pattern of the array (i.e., the angular sensitivity of the array) may be adjusted by varying one or more parameters. According to the embodiment, the signal-to-noise ratio of the array is enhanced by evaluating the one or more parameters which correspond to advantageous angular orientations of one or more directivity pattern nulls. The advantageous orientations comprise a substantial alignment of the nulls with sources of noise to reduce microphone array output signal level due to noise. The evaluation of parameters is performed under a constraint that the orientation of the nulls be restricted to a predetermined angular region of space termed the background. The one or more evaluated parameters are used to modify output signals of one or more microphones of the array to realize null orientations which reduce noise sensitivity. An array output signal is formed based on one or more modified output signals and zero or more unmodified microphone output signals.
FIGS. 1(a)-1(c) present three representations of illustrative background and foreground configurations.
FIG. 2 presents an illustrative sensitivity pattern of an array in accordance with the present invention.
FIG. 3 presents an illustrative embodiment of the present invention.
FIG. 4 presents a flow diagram of software for implementing a third embodiment of the present invention.
FIG. 5 presents a third illustrative embodiment of the present invention.
FIGS. 6(a) and 6(b) present analog circuitry for implementing β saturation of the embodiment of FIG. 5 and its input/output characteristic, respectively.
FIG. 7 presents a fourth illustrative embodiment of the present invention.
FIG. 8 presents a polyphase filterbank implementation of a β computer presented in FIG. 7.
FIG. 9 presents an illustrative window of coefficients for use by the windowing processor presented in FIG. 8.
FIG. 10 presents a fast convolutional procedure implementing a filterbank and scaling and summing circuits presented in FIG. 7.
FIG. 11 presents a fifth illustrative embodiment of the present invention.
FIG. 12 presents a sixth illustrative embodiment of the present invention.
Each illustrative embodiment discussed below comprises a microphone array which exhibits differing sensitivity to sound depending on the direction from which such sound impinges upon the array. For example, for undesired sound impinging upon the array from a selected angular region of space termed the background, the embodiments provide adaptive attenuation of array response to such sound impinging on the array. Such adaptive attenuation is provided by adaptively orienting one or more directivity pattern nulls to substantially align with the angular orientation(s) from which undesired sound impinges upon the array. This adaptive orientation is performed under a constraint that angular orientation of the null(s) be limited to the predetermined background.
For sound not impinging upon the array from an angular orientation within the background region, the embodiments provide substantially unattenuated sensitivity. The region of space not the background is termed the foreground. Because of the difference between array response to sound in the background and foreground, it is advantageous to physically orient the array such that desired sound impinges on the array from the foreground while undesired sound impinges on the array from the background.
FIG. 1 presents three representations of illustrative background and foreground configurations in two dimensions. In FIG. 1(a), the foreground is defined by the shaded angular region -45°<θ<45°. The letter "A" indicates the position of the array (i.e., at the origin), the letter "x" indicates the position of the desired source, and letter "y" indicates the position of the undesired noise source. In FIG. 1(b), the foreground is defined by the angular region -90°<θ<90°. In FIG. 1(c), the foreground is defined by the angular region -160°<θ<120°. The foreground/background combination of FIG. 1(b) is used with the illustrative embodiments discussed below. As such, the embodiments are sensitive to desired sound from the angular region -90°<θ<90° (foreground) and can adaptively place nulls within the region 90°<θ<270° to mitigate the effects of noise from this region (background).
FIG. 2 presents an illustrative directivity pattern of an array shown in two-dimensions in accordance with the present invention. The sensitivity pattern is superimposed on the foreground/background configuration of FIG. 2(b). As shown in FIG. 2, array A has a substantially uniform sensitivity (as a function of θ) in the foreground region to the desired source of sound DS. In the background region, however, the sensitivity pattern exhibits a null at approximately 180°±45°, which is substantially coincident with the two-dimensional angular position of the noise source NS. Because of this substantial coincidence, the noise source NS contributes less to the array output relative to other sources not aligned with the null. The illustrative embodiments of the present invention automatically adjust their directivity patterns to locate pattern nulls in angular orientations to mitigate the effect of noise on array output. This adjustment is made under the constraint that the nulls be limited to the background region of space adjacent to the array. This constraint prevents the nulls from migrating into the foreground and substantially affecting the response of the array to desired sound.
As stated above, FIG. 2 presents a directivity pattern in two-dimensions. This two-dimensional perspective is a projection of a three-dimensional directivity pattern onto a plane in which the array A lies. Thus, the sources DS and NS may lie in the plane itself or may have two-dimensional projections onto the plane as shown. Also, the illustrative directivity pattern null is shown as a two-dimensional projection. The three-dimensional directivity pattern may be envisioned as a three-dimensional surface obtained by rotating the two-dimensional pattern projection about the 0°-180° axis. In three dimensions, the illustrative null may be envisioned as a cone with the given angular orientation, 180°±45°. While directivity patterns are presented in two-dimensional space, it will be readily apparent to those of skill in the art that the present invention is generally applicable to three-dimensional arrangements of arrays, directivity patterns, and desired and undesired sources.
In the context of the present invention, there is no requirement that desired sources be located in the foreground or that undesired sources be located in the background. For example, as stated above the present invention has applicability to situations where desired acoustic energy impinges upon the array A from any direction within the foreground region (regardless of the location of the desired source(s)) and where undesired acoustic energy impinges on the array from any direction within the background region (regardless of the location of the undesired source(s)). Such situations may be caused by, e.g., reflections of acoustic energy (for example, a noise source not itself in the background may radiate acoustic energy which, due to reflection, impinges upon the array from some direction within the background). The present invention has applicability to still other situations where, e.g., both the desired source and the undesired source are located in the background (or the foreground). Embodiments of the invention would still adapt null position (constrained to the background) to reduce array output. Such possible configurations and situations notwithstanding, the illustrative embodiments of the present invention are presented in the context of desired sources located in the foreground and undesired sources located in the background for purposes of inventive concept presentation clarity.
The illustrative embodiments of the present invention are presented as comprising individual functional blocks (including functional blocks labeled as "processors") to aid in clarifying the explanation of the invention. The functions these blocks represent may be provided through the use of either shared or dedicated hardware, including, but not limited to, hardware capable of executing software. For example, the functions of blocks presented in FIGS. 3, 7, 8, 10, 11 and 12 may be provided by a single shared processor. (Use of the term "processor" should not be construed to refer exclusively to hardware capable of executing software.)
Illustrative embodiments may comprise digital signal processor (DSP) hardware, such as the AT&T DSP16 or DSP32C, read-only memory (ROM) for storing software performing the operations discussed below, and random access memory (RAM) for storing DSP results. Very large scale integration (VLSI) hardware embodiments, as well as custom VLSI circuitry in combination with a general purpose DSP circuit, may also be provided.
B. A First Illustrative Embodiment
FIG. 3 presents an illustrative embodiment of the present invention. In this embodiment, a microphone array is formed from back-to-back cardioid sensors. Each cardioid sensor is formed by a differential arrangement of two omnidirectional microphones. The microphone array receives a plane-wave acoustic signal, s(t), incident to the array at angle θ.
As shown in the Figure, the embodiment comprises a pair of omnidirectional microphones 10, 12 separated by a distance, d. The microphones of the embodiment are Bruel & Kjaer Model 4183 microphones. Distance d is 1.5 cm. Each microphone 10, 12 is coupled to a preamplifier 14,16, respectively. Preamplifier 14, 16 provides 40 dB of gain to the microphone output signal.
The output of each preamplifier 14, 16 is provided to a conventional analog-to-digital (A/D) converter 20, 25. The A/D converters 20,25 convert analog microphone output signals into digital signals for use in the balance of the embodiment. The sampling rate employed by the A/D converters 20, 25 is 22.05 kHz.
Delay lines 30, 25 introduce signal delays needed to form the cardioid sensors of the embodiment. Subtraction circuit 40 forms the back cardioid output signal, cB (t), by subtracting a delayed output of microphone 12 from an undelayed output of microphone 10. Subtraction circuit 45 forms the front cardioid output signal, cF (t), by subtracting a delayed output of microphone 10 from an undelayed output of microphone 12.
As stated above, the sampling rate of the A/D converters 20, 25 is 22.05 kHz. This rate allows advantageous formation of back-to-back cardioid sensors by appropriately subtracting present samples from previous samples. By setting the sampling period of the A/D converters to d/c, where d is the distance between the omni-directional microphones and c is the speed of sound, successive signal samples needed to form each cardioid sensor are obtained from the successive samples from the A/D converter.
The output signals from the subtraction circuits 40, 45 are provided to β processor 50. β processor 50 computes a gain β for application to signal cB (t) by amplifier 55. The scaled signal, βcB (t), is then subtracted from front cardioid output signal, cF (t), by subtraction circuit 60 to form array output signal, y(t).
Output signal y(t) is then filtered by lowpass filter 65. Lowpass filter 65 has a 5 kHz cutoff frequency. Lowpass filter 65 is used to attenuate signals that are above the highest design frequency for the array.
The forward and backward facing cardioid sensors may be described mathematically with a frequency domain representation as follows: ##EQU1## and the spatial origin is at the array center. Normalizing the array output signal by the input signal spectrum, S(ω), results in the following expression: ##EQU2## C. Determination of β
As shown in FIG. 3, the illustrative embodiment of the present invention includes a β processor 50 for determining the scale factor β used in adjusting the directivity pattern of the array. To allow the array to advantageously differentiate between desired foreground sources of acoustic energy and undesirable background noise sources, directivity pattern nulls are constrained to be within a defined spatial region. In the illustrative embodiment, the desired source of sound is radiating in the front half-plane of the array (that is, the foreground is defined by -90<θ<90). The undesired noise source is radiating in the rear half-plane of the array (that is, the background is defined by 90<θ<270). β processor 50 first computes a value for β and then constrains β to be 0<β<1 which effectuates a limitation on the placement of a directivity pattern null to be in the rear half-plane. For the first illustrative embodiment, θnull, the angular orientation of a directivity pattern null, is related to β as follows: ##EQU3## Note that for β=1, θnull =90° and for β=0, θnull =180°.
A value for β is computed by β processor 50 according to any of the following illustrative relationships.
1. Optimum β
The optimum value of β is defined as that value of β which minimizes the mean square value of the array output. The output signal of the illustrative back-to-back cardioid embodiment is:
y(n)=cF (n)-βcB (n). (5)
The value of β determined by processor 50 which minimizes array output is: ##EQU4## This result for optimum β is a finite time estimate of the optimum Wiener filter for a filter of length one.
2. Updating β with LMS Adaptation
Values for β may be obtained using a least mean squares (LMS) adaptive scheme. Given the output expression for the back-to-back cardioid array of FIG. 3,
y(n)=cF (n)-βcB (n) (7)
the LMS update expression for β is
β(n+1)=β(n)+2μy(n)cB (n), (8)
where μ is the update step-size (μ<1; the larger the μ the faster the convergence). The LMS update may be modified to include a normalized update step-size so that explicit convergence bounds for μ may be independent of the input power. The LMS update of β with a normalized μ is: ##EQU5## where the brackets indicate a time average, and where if <cB 2 (n)> is close to zero, the quotient is not formed and μ is set to zero.
3. Updating β with Newton's Technique
Newton's technique is a special case of LMS where μ is a function of the input. The update expression for β is: ##EQU6## where cB (n) is not equal to zero. The noise sensitivity of this system may be reduced by introducing a constant multiplier 0≦μ≦1 to the update term, y(n)/cB (n).
D. A Software Implementation of the First Embodiment
While the illustrative embodiment presented above may be implemented largely in hardware as described, the embodiment may be implemented in software running on a DSP, such as the AT&T DSP32C, as stated above. FIG. 4 presents a flow diagram of software for implementing a second illustrative embodiment of the present invention for optimum β.
According to step 110 of FIG. 4, the first task for the DSP is to acquire from each channel (i.e., from each A/D converter associated with a microphone) a sample of the microphone signals. These acquired samples (one for each channel) are current samples at time n. These sample are buffered into memory for present and future use (see step 115). Microphone samples previously buffered at time n-1 are made available from buffer memory. Thus, the buffer memory serves as the delay utilized for forming the cardioid sensors.
Next, both the front and back cardioid output signal samples are formed (see step 120). The front cardioid sensor signal sample, cF (n), is formed by subtracting a delayed sample (valid at time n-1) from the back microphone (via a buffer memory) from a current sample (valid at time n) from the front microphone. The back cardioid sensor signal sample, cB (n), is formed by subtracting a delayed sample (valid at time n-1) from the front microphone (via a buffer memory) from a current sample (valid at time n) from the back microphone.
The operations prefatory to the computation of scale factor β are performed at steps 125 and 130. Signals cB 2 (n) and cF (n)cB (n) are first computed (step 125). Each of these signals is then averaged over a block of N samples, where N is illustratively 1,000 samples (step 130). The size of N affects the speed of null adaptation to moving sources of noise. Small values of N can lead to null adaptation jitter, while large values of N can lead to slow adaptation rates. Advantageously, N, should be chosen as large as possible while maintaining sufficient null tracking speed for the given application.
At step 135, the block average of the cross-product of back and front cardioid sensor signals is divided by the block average of the square of the back cardioid sensor signal. The result is the ratio, β, as described in expression (6). The value of β is then constrained to be within the range of zero and one. This constraint is accomplished by setting β=1 if β is calculated to be a number greater than one, and setting β=0 if β is calculated to be a number less than zero. By constraining β in this way, the null of the array is constrained to be in the rear half-plane of the array's sensitivity pattern.
The output sample of the array, y(n), is formed (step 140) in two steps. First, the back cardioid signal sample is scaled by the computed and constrained (if necessary) value of β. Second, the scaled back cardioid signal sample is subtracted from the front cardioid signal sample.
Output signal y(n) is then filtered (step 145) by a lowpass filter having a 5 kHz cutoff frequency. As stated above, the lowpass filter is used to attenuate signals that are above the highest design frequency for the array. The filtered output signal is then provided to a D/A converter (step 150) for use by conventional analog devices. The software process continues (step 155) if there is a further input sample from the A/D converters to process. Otherwise, the process ends.
E. An Illustrative Analog Embodiment
The present invention may be implemented with analog components. FIG. 5 presents such an illustrative implementation comprising conventional analog multipliers 510, 530, 540, an analog integrator 550, an analog summer 520, and a non-inverting amplifier circuit 560 shown in FIG. 6(a) having input/output characteristic shown in FIG. 6(b) (wherein the saturation voltage VL =β is set by the user to define the foreground/background relationship). Voltage VL is controlled by a potentiometer setting as shown. The circuit of FIG. 5 operates in accordance with continuous-time versions of equations (7) and (8), wherein β is determined in an LMS fashion.
F. A Fourth Illustrative Embodiment
A fourth illustrative embodiment of the present invention is directed to a subband implementation of the invention. The embodiment may be advantageously employed in situations where there are multiple noise sources radiating acoustic energy at different frequencies. According to the embodiment, each subband has its own directivity pattern including a null. The embodiment computes a value for β (or a related parameter) on a subband-by-subband basis. Parameters are evaluated to provide an angular orientation of a given subband null. This orientation helps reduce microphone array output level by reducing the array response to noise in a given subband. The nulls of the individual subbands are not generally coincident, since noise sources (which provide acoustic noise energy at differing frequencies) may be located in different angular directions. However there is no reason why two or more subband nulls cannot be substantially coincident.
The fourth illustrative embodiment of the present invention is presented in FIG. 7. The embodiment is identical to that of FIG. 3 insofar as the microphones 10, 12, preamplifiers 14, 16, A/D converters 20, 25, and delays 30, 35 are concerned. These components are not repeated in FIG. 7 so as to clarify the presentation of the embodiment. However, subtraction circuits 40, 45 are shown for purposes of orienting the reader with the similarity of this fourth embodiment to that of FIG. 3.
As shown in the Figure, the back cardioid sensor output signal, cB (n), is provided to a β-processor 220 as well as a filterbank 215. Filterbank 215 resolves the signal cB (n) into M/2+1 subband component signals. Each subband component signal is scaled by a subband version of β. The scaled subband component signals are then summed by summing circuit 230. The output signal of summing circuit 230 is then subtracted from a delayed version of the front cardioid sensor output signal, cF (n), to form array output signal, y(n). Illustratively, M=32. The delay line 210 is chosen to realize a delay commensurate with the processing delay of the branch of the embodiment concerned with the back cardioid output signal, cB (n).
The β-processor 220 of FIG. 7 comprises a polyphase filterbank as illustrated in FIG. 8.
As shown in FIG. 8, the back cardioid sensor output signal, cB (n), is applied to windowing processor 410. Windowing processor applies a window of coefficients presented in FIG. 9 to incoming samples of cB (n) to form the M output signals, pm (n), shown in FIG. 8. Windowing processor 410 comprises a buffer for storing 2M-1 samples of cB (n), a read-only memory for storing window coefficients, w(n), and a processor for forming the products/sums of coefficients and signals. Windowing processor 410 generates signals pm (n) according to the following relationships:
p0 (n)=cB (n-M)w(0)
p1 (n)=cB (n-1)w(-M+1)+cB (n-M-1)w(1)
p2 (n)=cB (n-2)w(-M+2)+cB (n-M-2)w(2)
pM-1 (n)=cB (n-M+1)w(-1)+cB (n-2M+1)w(m-1). (11)
The output signals of windowing processor 410, pm (n), are applied to Fast Fourier Transform (FFT) processor 420. Processor 420 takes a conventional M-point FFT based on the M signals pm (n). What results are M FFT signals. Of these signals, two are real valued signals and are labeled as v0 (n) and vM/2 (n). Each of the balance of the signals is complex. Real valued signals, v1 (n) through vM/2-1 (n) are formed by the sum of an FFT signal and its complex conjugate, as shown in the FIG. 8.
Real-valued signals v0 (n), . . . , vM/2 (n) are provided to β-update processor 430. β-update processor 430 updates values of β for each subband according to the following relation: ##EQU7## where μ is the update stepsize, illustratively 0.1 (however, μ may be set equal to zero and the quotient not formed when the denominator of (12) is close to zero). The updated value of βm (n) is then saturated as discussed above. That is, for 0<m<M/2, ##EQU8## Advantageously, the computations described by expressions (11) through (13) are performed once every M samples to reduce computational load.
Those components which appear in the filterbank 215 and scaling and summing section 212 of FIG. 7 may be realized by a fast convolution technique illustrated by the block diagram of FIG. 10.
As shown in FIG. 10, β-processor provides the subband values of β to β-to-γ processor 320. β-to-γ processor 320 generates 4M fast convolution coefficients, γ, which are equivalent to the set of β coefficients from processor 430. The γ coefficients are generated by (i) computing an impulse response (of length 2M-1) of the filter which is block 212 (of FIG. 7) as a function of the values of β and (ii) computing the Fast Fourier Transform (FFT) (of size 4M) of the computed impulse response. The computed FFT coefficients are the 4M γ's. (Alternatively, due to the symmetry of the window used in the computation of the subband β values, there is a symmetry in the values of the γ coefficients which can be exploited to reduce the size of the FFT to 2M.)
The 4M γ coefficients are applied to a frequency domain representation of the back cardioid sensor signal, cB (n). This frequency domain representation is provided by FFT processor 310 which performs a 4M FFT. The 4M γ coefficients are used to scale the 4M FFT coefficients as shown in FIG. 10. The scaled FFT coefficients are then processed by FFT-1 processor 330. The output of FFT-1 processor 330 (and block 212) is then provided to the summing circuit 235 for subtraction from the delayed cF (n) signal (as shown in FIG. 7). The size of the FFT and FFT-1 may also be reduced by exploiting the symmetry of the γ coefficients.
G. Alternative Embodiments
While the illustrative embodiments presented above concern back-to-back cardioid sensors, those of ordinary skill in the art will appreciate that other array configurations in accordance with the present invention are possible. One such array configuration comprises a combination of an omnidirectional sensor and a dipole sensor to form an adaptive first order differential microphone array. Such a combination is presented in FIG. 11. β is updated according to the following expression:
Another such array configuration comprises a combination of a dipole sensor and a cardioid sensor to again form an adaptive first order differential microphone array. Such a combination is presented in FIG. 12. β is updated according to the following expression:
Although a number of specific embodiments of this invention have been shown and described herein, it is to be understood that these embodiments are merely illustrative of the many possible specific arrangements which can be devised in application of the principles of the invention. Numerous and varied other arrangements can be devised in accordance with these principles by those of ordinary skill in the art without departing from the spirit and scope of the invention.
|Cited Patent||Filing date||Publication date||Applicant||Title|
|US4485484 *||Oct 28, 1982||Nov 27, 1984||At&T Bell Laboratories||Directable microphone system|
|US4536887 *||Oct 7, 1983||Aug 20, 1985||Nippon Telegraph & Telephone Public Corporation||Microphone-array apparatus and method for extracting desired signal|
|US4653102 *||Nov 5, 1985||Mar 24, 1987||Position Orientation Systems||Directional microphone system|
|US4802227 *||Apr 3, 1987||Jan 31, 1989||American Telephone And Telegraph Company||Noise reduction processing arrangement for microphone arrays|
|US4956867 *||Apr 20, 1989||Sep 11, 1990||Massachusetts Institute Of Technology||Adaptive beamforming for noise reduction|
|US5267320 *||Mar 12, 1992||Nov 30, 1993||Ricoh Company, Ltd.||Noise controller which noise-controls movable point|
|1||*||European Search Report dated Feb. 21, 1995, corresponding European Patent Application 94307855.0.|
|2||L. J. Griffiths et al., "An Alternative Approach to Linearly Constrained Adaptive Beamforming," IEEE Trans. Antennas Propag., vol. AP-30, 27-34 (Jan. 1982).|
|3||*||L. J. Griffiths et al., An Alternative Approach to Linearly Constrained Adaptive Beamforming, IEEE Trans. Antennas Propag., vol. AP 30, 27 34 (Jan. 1982).|
|4||L. J. Griffiths, "A Simple Adaptive Algorithm for Real-Time Processing in Antenna Arrays," Proc. IEEE, vol. 57, 1696-1704 (Oct. 1969).|
|5||*||L. J. Griffiths, A Simple Adaptive Algorithm for Real Time Processing in Antenna Arrays, Proc. IEEE, vol. 57, 1696 1704 (Oct. 1969).|
|6||O. L. Frost III, "An Algorithm for Linearly Constrained Adaptive Array Processing," Proc. IEEE, vol. 60, 926-935 (Aug. 1972).|
|7||*||O. L. Frost III, An Algorithm for Linearly Constrained Adaptive Array Processing, Proc. IEEE, vol. 60, 926 935 (Aug. 1972).|
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US5647006 *||Jun 22, 1995||Jul 8, 1997||U.S. Philips Corporation||Mobile radio terminal comprising a speech|
|US5675655 *||Apr 10, 1995||Oct 7, 1997||Canon Kabushiki Kaisha||Sound input apparatus|
|US5740256 *||Dec 11, 1996||Apr 14, 1998||U.S. Philips Corporation||Adaptive noise cancelling arrangement, a noise reduction system and a transceiver|
|US5825898 *||Jun 27, 1996||Oct 20, 1998||Lamar Signal Processing Ltd.||System and method for adaptive interference cancelling|
|US5886656 *||May 24, 1996||Mar 23, 1999||Sgs-Thomson Microelectronics, S.R.L.||Digital microphone device|
|US5933807 *||Dec 15, 1995||Aug 3, 1999||Nitsuko Corporation||Screen control apparatus and screen control method|
|US6072881 *||Jun 9, 1997||Jun 6, 2000||Chiefs Voice Incorporated||Microphone noise rejection system|
|US6094150 *||Aug 6, 1998||Jul 25, 2000||Mitsubishi Heavy Industries, Ltd.||System and method of measuring noise of mobile body using a plurality microphones|
|US6178248||Apr 14, 1997||Jan 23, 2001||Andrea Electronics Corporation||Dual-processing interference cancelling system and method|
|US6222927 *||Jun 19, 1996||Apr 24, 2001||The University Of Illinois||Binaural signal processing system and method|
|US6363345||Feb 18, 1999||Mar 26, 2002||Andrea Electronics Corporation||System, method and apparatus for cancelling noise|
|US6430295 *||Jul 11, 1997||Aug 6, 2002||Telefonaktiebolaget Lm Ericsson (Publ)||Methods and apparatus for measuring signal level and delay at multiple sensors|
|US6449586 *||Jul 31, 1998||Sep 10, 2002||Nec Corporation||Control method of adaptive array and adaptive array apparatus|
|US6549586 *||Apr 12, 1999||Apr 15, 2003||Telefonaktiebolaget L M Ericsson||System and method for dual microphone signal noise reduction using spectral subtraction|
|US6584203 *||Oct 30, 2001||Jun 24, 2003||Agere Systems Inc.||Second-order adaptive differential microphone array|
|US6594367||Oct 25, 1999||Jul 15, 2003||Andrea Electronics Corporation||Super directional beamforming design and implementation|
|US6600824 *||Jul 26, 2000||Jul 29, 2003||Fujitsu Limited||Microphone array system|
|US6603861 *||Oct 7, 1998||Aug 5, 2003||Phonak Ag||Method for electronically beam forming acoustical signals and acoustical sensor apparatus|
|US6717991 *||Jan 28, 2000||Apr 6, 2004||Telefonaktiebolaget Lm Ericsson (Publ)||System and method for dual microphone signal noise reduction using spectral subtraction|
|US6748086 *||Oct 19, 2000||Jun 8, 2004||Lear Corporation||Cabin communication system without acoustic echo cancellation|
|US6836243||Aug 31, 2001||Dec 28, 2004||Nokia Corporation||System and method for processing a signal being emitted from a target signal source into a noisy environment|
|US6865275 *||Apr 3, 2000||Mar 8, 2005||Phonak Ag||Method to determine the transfer characteristic of a microphone system, and microphone system|
|US6912289||Oct 9, 2003||Jun 28, 2005||Unitron Hearing Ltd.||Hearing aid and processes for adaptively processing signals therein|
|US6950528||Mar 25, 2004||Sep 27, 2005||Siemens Audiologische Technik Gmbh||Method and apparatus for suppressing an acoustic interference signal in an incoming audio signal|
|US6978159||Mar 13, 2001||Dec 20, 2005||Board Of Trustees Of The University Of Illinois||Binaural signal processing using multiple acoustic sensors and digital filtering|
|US6987856 *||Nov 16, 1998||Jan 17, 2006||Board Of Trustees Of The University Of Illinois||Binaural signal processing techniques|
|US7010134||Oct 16, 2003||Mar 7, 2006||Widex A/S||Hearing aid, a method of controlling a hearing aid, and a noise reduction system for a hearing aid|
|US7076072||Apr 9, 2003||Jul 11, 2006||Board Of Trustees For The University Of Illinois||Systems and methods for interference-suppression with directional sensing patterns|
|US7123727||Oct 30, 2001||Oct 17, 2006||Agere Systems Inc.||Adaptive close-talking differential microphone array|
|US7133530||Feb 2, 2001||Nov 7, 2006||Industrial Research Limited||Microphone arrays for high resolution sound field recording|
|US7212642||Dec 18, 2003||May 1, 2007||Oticon A/S||Microphone system with directional response|
|US7212643||Feb 10, 2004||May 1, 2007||Phonak Ag||Real-ear zoom hearing device|
|US7274794||Aug 10, 2001||Sep 25, 2007||Sonic Innovations, Inc.||Sound processing system including forward filter that exhibits arbitrary directivity and gradient response in single wave sound environment|
|US7280627||Dec 8, 2003||Oct 9, 2007||The Johns Hopkins University||Constrained data-adaptive signal rejector|
|US7340068||Feb 19, 2003||Mar 4, 2008||Oticon A/S||Device and method for detecting wind noise|
|US7363334||Aug 28, 2003||Apr 22, 2008||Accoutic Processing Technology, Inc.||Digital signal-processing structure and methodology featuring engine-instantiated, wave-digital-filter componentry, and fabrication thereof|
|US7386135||Jul 26, 2002||Jun 10, 2008||Dashen Fan||Cardioid beam with a desired null based acoustic devices, systems and methods|
|US7409068||Mar 6, 2003||Aug 5, 2008||Sound Design Technologies, Ltd.||Low-noise directional microphone system|
|US7512448||Jan 10, 2003||Mar 31, 2009||Phonak Ag||Electrode placement for wireless intrabody communication between components of a hearing system|
|US7577266 *||Jul 11, 2006||Aug 18, 2009||The Board Of Trustees Of The University Of Illinois||Systems and methods for interference suppression with directional sensing patterns|
|US7613309||Nov 7, 2002||Nov 3, 2009||Carolyn T. Bilger, legal representative||Interference suppression techniques|
|US7751575 *||Sep 25, 2003||Jul 6, 2010||Baumhauer Jr John C||Microphone system for communication devices|
|US7817805||Oct 19, 2010||Motion Computing, Inc.||System and method for steering the directional response of a microphone to a moving acoustic source|
|US7848529 *||Jan 11, 2007||Dec 7, 2010||Fortemedia, Inc.||Broadside small array microphone beamforming unit|
|US7889873||Jan 27, 2005||Feb 15, 2011||Dpa Microphones A/S||Microphone aperture|
|US7929721||Oct 22, 2007||Apr 19, 2011||Siemens Audiologische Technik Gmbh||Hearing aid with directional microphone system, and method for operating a hearing aid|
|US7945064||May 17, 2011||Board Of Trustees Of The University Of Illinois||Intrabody communication with ultrasound|
|US8019091 *||Sep 18, 2003||Sep 13, 2011||Aliphcom, Inc.||Voice activity detector (VAD) -based multiple-microphone acoustic noise suppression|
|US8019121||Sep 13, 2011||Sony Computer Entertainment Inc.||Method and system for processing intensity from input devices for interfacing with a computer program|
|US8035629||Dec 1, 2006||Oct 11, 2011||Sony Computer Entertainment Inc.||Hand-held computer interactive device|
|US8072470||May 29, 2003||Dec 6, 2011||Sony Computer Entertainment Inc.||System and method for providing a real-time three-dimensional interactive environment|
|US8085339||Dec 27, 2011||Sony Computer Entertainment Inc.||Method and apparatus for optimizing capture device settings through depth information|
|US8098844||Nov 5, 2006||Jan 17, 2012||Mh Acoustics, Llc||Dual-microphone spatial noise suppression|
|US8139787||Sep 8, 2006||Mar 20, 2012||Simon Haykin||Method and device for binaural signal enhancement|
|US8142288||May 8, 2009||Mar 27, 2012||Sony Computer Entertainment America Llc||Base station movement detection and compensation|
|US8188968||May 29, 2012||Sony Computer Entertainment Inc.||Methods for interfacing with a program using a light input device|
|US8238593||Jun 25, 2007||Aug 7, 2012||Gn Resound A/S||Hearing instrument with adaptive directional signal processing|
|US8249284||Aug 21, 2012||Phonak Ag||Hearing system and method for deriving information on an acoustic scene|
|US8287373||Apr 17, 2009||Oct 16, 2012||Sony Computer Entertainment Inc.||Control device for communicating visual information|
|US8310656||Nov 13, 2012||Sony Computer Entertainment America Llc||Mapping movements of a hand-held controller to the two-dimensional image plane of a display screen|
|US8313380||May 6, 2006||Nov 20, 2012||Sony Computer Entertainment America Llc||Scheme for translating movements of a hand-held controller into inputs for a system|
|US8323106||Jun 24, 2008||Dec 4, 2012||Sony Computer Entertainment America Llc||Determination of controller three-dimensional location using image analysis and ultrasonic communication|
|US8331582||Aug 11, 2004||Dec 11, 2012||Wolfson Dynamic Hearing Pty Ltd||Method and apparatus for producing adaptive directional signals|
|US8342963||Apr 10, 2009||Jan 1, 2013||Sony Computer Entertainment America Inc.||Methods and systems for enabling control of artificial intelligence game characters|
|US8358789||Nov 4, 2009||Jan 22, 2013||Siemens Medical Instruments Pte. Ltd.||Adaptive microphone system for a hearing device and associated operating method|
|US8368753||Feb 5, 2013||Sony Computer Entertainment America Llc||Controller with an integrated depth camera|
|US8393964||May 8, 2009||Mar 12, 2013||Sony Computer Entertainment America Llc||Base station for position location|
|US8494177 *||Jun 13, 2008||Jul 23, 2013||Aliphcom||Virtual microphone array systems using dual omindirectional microphone array (DOMA)|
|US8503691 *||Jun 13, 2008||Aug 6, 2013||Aliphcom||Virtual microphone arrays using dual omnidirectional microphone array (DOMA)|
|US8503692 *||Jun 13, 2008||Aug 6, 2013||Aliphcom||Forming virtual microphone arrays using dual omnidirectional microphone array (DOMA)|
|US8526647||Jun 1, 2010||Sep 3, 2013||Oticon A/S||Listening device providing enhanced localization cues, its use and a method|
|US8527657||Mar 20, 2009||Sep 3, 2013||Sony Computer Entertainment America Llc||Methods and systems for dynamically adjusting update rates in multi-player network gaming|
|US8542907||Dec 15, 2008||Sep 24, 2013||Sony Computer Entertainment America Llc||Dynamic three-dimensional object mapping for user-defined control device|
|US8547401||Aug 19, 2004||Oct 1, 2013||Sony Computer Entertainment Inc.||Portable augmented reality device and method|
|US8568230||Nov 10, 2009||Oct 29, 2013||Sony Entertainment Computer Inc.||Methods for directing pointing detection conveyed by user when interfacing with a computer program|
|US8570378||Oct 30, 2008||Oct 29, 2013||Sony Computer Entertainment Inc.||Method and apparatus for tracking three-dimensional movements of an object using a depth sensing camera|
|US8577055||Jan 22, 2013||Nov 5, 2013||Samsung Electronics Co., Ltd.||Sound source signal filtering apparatus based on calculated distance between microphone and sound source|
|US8682018 *||Mar 30, 2012||Mar 25, 2014||Aliphcom||Microphone array with rear venting|
|US8686939||May 6, 2006||Apr 1, 2014||Sony Computer Entertainment Inc.||System, method, and apparatus for three-dimensional input control|
|US8693703 *||May 2, 2008||Apr 8, 2014||Gn Netcom A/S||Method of combining at least two audio signals and a microphone system comprising at least two microphones|
|US8781151||Aug 16, 2007||Jul 15, 2014||Sony Computer Entertainment Inc.||Object detection using video input combined with tilt angle information|
|US8797260||May 6, 2006||Aug 5, 2014||Sony Computer Entertainment Inc.||Inertially trackable hand-held controller|
|US8804979||Oct 6, 2011||Aug 12, 2014||Oticon A/S||Method of determining parameters in an adaptive audio processing algorithm and an audio processing system|
|US8830375||Jun 30, 2010||Sep 9, 2014||Lester F. Ludwig||Vignetted optoelectronic array for use in synthetic image formation via signal processing, lensless cameras, and integrated camera-displays|
|US8837746 *||Jun 13, 2008||Sep 16, 2014||Aliphcom||Dual omnidirectional microphone array (DOMA)|
|US8840470||Feb 24, 2009||Sep 23, 2014||Sony Computer Entertainment America Llc||Methods for capturing depth data of a scene and applying computer actions|
|US8942387 *||Mar 9, 2007||Jan 27, 2015||Mh Acoustics Llc||Noise-reducing directional microphone array|
|US8976265||Oct 26, 2011||Mar 10, 2015||Sony Computer Entertainment Inc.||Apparatus for image and sound capture in a game environment|
|US9064502||Mar 10, 2011||Jun 23, 2015||Oticon A/S||Speech intelligibility predictor and applications thereof|
|US9066186||Mar 14, 2012||Jun 23, 2015||Aliphcom||Light-based detection for acoustic applications|
|US9082411||Dec 7, 2011||Jul 14, 2015||Oticon A/S||Method to reduce artifacts in algorithms with fast-varying gain|
|US9094496 *||Oct 1, 2010||Jul 28, 2015||Avaya Inc.||System and method for stereophonic acoustic echo cancellation|
|US9099094 *||Jun 27, 2008||Aug 4, 2015||Aliphcom||Microphone array with rear venting|
|US9167359||Jul 23, 2010||Oct 20, 2015||Sonova Ag||Hearing system and method for operating a hearing system|
|US9177387||Feb 11, 2003||Nov 3, 2015||Sony Computer Entertainment Inc.||Method and apparatus for real time motion capture|
|US9182475||Oct 29, 2013||Nov 10, 2015||Samsung Electronics Co., Ltd.||Sound source signal filtering apparatus based on calculated distance between microphone and sound source|
|US9196261||Feb 28, 2011||Nov 24, 2015||Aliphcom||Voice activity detector (VAD)—based multiple-microphone acoustic noise suppression|
|US9202475||Oct 15, 2012||Dec 1, 2015||Mh Acoustics Llc||Noise-reducing directional microphone ARRAYOCO|
|US9263062||Aug 5, 2013||Feb 16, 2016||AplihCom||Vibration sensor and acoustic voice activity detection systems (VADS) for use with electronic systems|
|US9264018||May 25, 2013||Feb 16, 2016||Acoustic Processing Technology, Inc.||Digital signal-processing structure and methodology featuring engine-instantiated, wave-digital-filter cascading/chaining|
|US9301049||Aug 28, 2012||Mar 29, 2016||Mh Acoustics Llc||Noise-reducing directional microphone array|
|US9307332||Dec 2, 2010||Apr 5, 2016||Oticon A/S||Method for dynamic suppression of surrounding acoustic noise when listening to electrical inputs|
|US9338565||Oct 16, 2012||May 10, 2016||Oticon A/S||Listening system adapted for real-time communication providing spatial information in an audio stream|
|US9381424||Jan 11, 2011||Jul 5, 2016||Sony Interactive Entertainment America Llc||Scheme for translating movements of a hand-held controller into inputs for a system|
|US20020009203 *||Mar 30, 2001||Jan 24, 2002||Gamze Erten||Method and apparatus for voice signal extraction|
|US20020080684 *||Nov 16, 2001||Jun 27, 2002||Dimitri Donskoy||Large aperture vibration and acoustic sensor|
|US20030016835 *||Oct 30, 2001||Jan 23, 2003||Elko Gary W.||Adaptive close-talking differential microphone array|
|US20030061032 *||Sep 24, 2002||Mar 27, 2003||Clarity, Llc||Selective sound enhancement|
|US20030063758 *||Feb 2, 2001||Apr 3, 2003||Poletti Mark Alistair||Microphone arrays for high resolution sound field recording|
|US20030169891 *||Mar 6, 2003||Sep 11, 2003||Ryan Jim G.||Low-noise directional microphone system|
|US20040013038 *||Aug 31, 2001||Jan 22, 2004||Matti Kajala||System and method for processing a signal being emitted from a target signal source into a noisy environment|
|US20040081327 *||Oct 16, 2003||Apr 29, 2004||Widex A/S||Hearing aid, a method of controlling a hearing aid, and a noise reduction system for a hearing aid|
|US20040120429 *||Dec 8, 2003||Jun 24, 2004||Orlin David J.||Constrained data-adaptive signal rejector|
|US20040133421 *||Sep 18, 2003||Jul 8, 2004||Burnett Gregory C.||Voice activity detector (VAD) -based multiple-microphone acoustic noise suppression|
|US20040161120 *||Feb 19, 2003||Aug 19, 2004||Petersen Kim Spetzler||Device and method for detecting wind noise|
|US20040202339 *||Apr 9, 2003||Oct 14, 2004||O'brien, William D.||Intrabody communication with ultrasound|
|US20040240682 *||Mar 25, 2004||Dec 2, 2004||Eghart Fischer||Method and apparatus for suppressing an acoustic interference signal in an incoming audio signal|
|US20050050126 *||Aug 28, 2003||Mar 3, 2005||Acoustic Processing Technology, Inc.||Digital signal-processing structure and methodology featuring engine-instantiated, wave-digital-filter componentry, and fabrication thereof|
|US20050074129 *||Jul 26, 2002||Apr 7, 2005||Dashen Fan||Cardioid beam with a desired null based acoustic devices, systems and methods|
|US20050078842 *||Oct 9, 2003||Apr 14, 2005||Unitron Hearing Ltd.||Hearing aid and processes for adaptively processing signals therein|
|US20050175204 *||Feb 10, 2004||Aug 11, 2005||Friedrich Bock||Real-ear zoom hearing device|
|US20060115097 *||Dec 18, 2003||Jun 1, 2006||Oticon A/S||Microphone system with directional response|
|US20060115103 *||Apr 9, 2003||Jun 1, 2006||Feng Albert S||Systems and methods for interference-suppression with directional sensing patterns|
|US20060140415 *||Dec 23, 2004||Jun 29, 2006||Phonak||Method and system for providing active hearing protection|
|US20070014419 *||Aug 11, 2004||Jan 18, 2007||Dynamic Hearing Pty Ltd.||Method and apparatus for producing adaptive directional signals|
|US20070127753 *||Jul 11, 2006||Jun 7, 2007||Feng Albert S||Systems and methods for interference suppression with directional sensing patterns|
|US20070269064 *||Jul 21, 2006||Nov 22, 2007||Phonak Ag||Hearing system and method for deriving information on an acoustic scene|
|US20080044046 *||Oct 22, 2007||Feb 21, 2008||Siemens Audiologische Technik Gmbh||Hearing aid with directional microphone system, and method for operating a hearing aid|
|US20080170715 *||Jan 11, 2007||Jul 17, 2008||Fortemedia, Inc.||Broadside small array microphone beamforming unit|
|US20080260175 *||Nov 5, 2006||Oct 23, 2008||Mh Acoustics, Llc||Dual-Microphone Spatial Noise Suppression|
|US20080312918 *||Jun 18, 2008||Dec 18, 2008||Samsung Electronics Co., Ltd.||Voice performance evaluation system and method for long-distance voice recognition|
|US20090003623 *||Jun 13, 2008||Jan 1, 2009||Burnett Gregory C||Dual Omnidirectional Microphone Array (DOMA)|
|US20090003624 *||Jun 13, 2008||Jan 1, 2009||Burnett Gregory C||Dual Omnidirectional Microphone Array (DOMA)|
|US20090003625 *||Jun 13, 2008||Jan 1, 2009||Burnett Gregory C||Dual Omnidirectional Microphone Array (DOMA)|
|US20090003626 *||Jun 13, 2008||Jan 1, 2009||Burnett Gregory C||Dual Omnidirectional Microphone Array (DOMA)|
|US20090010450 *||Jun 27, 2008||Jan 8, 2009||Burnett Gregory C||Microphone Array With Rear Venting|
|US20090175466 *||Mar 9, 2007||Jul 9, 2009||Mh Acoustics, Llc||Noise-reducing directional microphone array|
|US20090226004 *||Jan 27, 2005||Sep 10, 2009||Soerensen Ole Moeller||Microphone aperture|
|US20090231425 *||Mar 17, 2008||Sep 17, 2009||Sony Computer Entertainment America||Controller with an integrated camera and methods for interfacing with an interactive application|
|US20090304203 *||Sep 8, 2006||Dec 10, 2009||Simon Haykin||Method and device for binaural signal enhancement|
|US20100033427 *||Feb 11, 2010||Sony Computer Entertainment Inc.||Computer Image and Audio Processing of Intensity and Input Devices for Interfacing with a Computer Program|
|US20100046776 *||Nov 4, 2009||Feb 25, 2010||Eghart Fischer||Adaptive microphone system for a hearing device and associated operating method|
|US20100056277 *||Mar 4, 2010||Sony Computer Entertainment Inc.||Methods for directing pointing detection conveyed by user when interfacing with a computer program|
|US20100097476 *||Dec 23, 2009||Apr 22, 2010||Sony Computer Entertainment Inc.||Method and Apparatus for Optimizing Capture Device Settings Through Depth Information|
|US20100144436 *||Apr 17, 2009||Jun 10, 2010||Sony Computer Entertainment Inc.||Control Device for Communicating Visual Information|
|US20100239100 *||Sep 23, 2010||Siemens Medical Instruments Pte. Ltd.||Method for adjusting a directional characteristic and a hearing apparatus|
|US20100285879 *||Nov 11, 2010||Sony Computer Entertainment America, Inc.||Base Station for Position Location|
|US20100285883 *||Nov 11, 2010||Sony Computer Entertainment America Inc.||Base Station Movement Detection and Compensation|
|US20100303267 *||Dec 2, 2010||Oticon A/S||Listening device providing enhanced localization cues, its use and a method|
|US20100314631 *||Jun 30, 2010||Dec 16, 2010||Avistar Communications Corporation||Display-pixel and photosensor-element device and method therefor|
|US20110032369 *||Jun 30, 2010||Feb 10, 2011||Avistar Communications Corporation||Vignetted optoelectronic array for use in synthetic image formation via signal processing, lensless cameras, and integrated camera-displays|
|US20110044460 *||May 2, 2008||Feb 24, 2011||Martin Rung||method of combining at least two audio signals and a microphone system comprising at least two microphones|
|US20110103626 *||Jun 25, 2007||May 5, 2011||Gn Resound A/S||Hearing Instrument with Adaptive Directional Signal Processing|
|US20110137649 *||Jun 9, 2011||Rasmussen Crilles Bak||method for dynamic suppression of surrounding acoustic noise when listening to electrical inputs|
|US20110223997 *||Sep 15, 2011||Sony Computer Entertainment Inc.||Method to detect and remove audio disturbances from audio signals captured at video game controllers|
|US20110224976 *||Sep 15, 2011||Taal Cees H||Speech intelligibility predictor and applications thereof|
|US20110311064 *||Dec 22, 2011||Avaya Inc.||System and method for stereophonic acoustic echo cancellation|
|US20120207322 *||Mar 30, 2012||Aug 16, 2012||Aliphcom||Microphone array with rear venting|
|US20120330653 *||May 30, 2012||Dec 27, 2012||Veovox Sa||Device and method for capturing and processing voice|
|US20140185824 *||Aug 5, 2013||Jul 3, 2014||Gregory C. Burnett||Forming virtual microphone arrays using dual omnidirectional microphone array (doma)|
|US20140244250 *||Feb 18, 2014||Aug 28, 2014||Kopin Corporation||Cardioid beam with a desired null based acoustic devices, systems, and methods|
|US20140286519 *||Mar 25, 2014||Sep 25, 2014||Aliphcom||Microphone array with rear venting|
|CN1669356B *||Jun 18, 2003||Sep 8, 2010||索尼爱立信移动通讯股份有限公司||Electronic devices, methods of operating the same, and computer program products for detecting noise in a signal based on a combination of spatial correlation and time correlation|
|DE10313330A1 *||Mar 25, 2003||Oct 21, 2004||Siemens Audiologische Technik Gmbh||Suppression of acoustic noise signal in hearing aid, by weighted combination of signals from microphones, normalization and selection of directional microphone signal having lowest interference signal content|
|DE10313330B4 *||Mar 25, 2003||Apr 14, 2005||Siemens Audiologische Technik Gmbh||Verfahren zur Unterdrückung mindestens eines akustischen Störsignals und Vorrichtung zur Durchführung des Verfahrens|
|DE10331956C5 *||Jul 16, 2003||Nov 18, 2010||Siemens Audiologische Technik Gmbh||Hörhilfegerät sowie Verfahren zum Betrieb eines Hörhilfegerätes mit einem Mikrofonsystem, bei dem unterschiedliche Richtcharakteistiken einstellbar sind|
|EP1448016A1 *||Feb 17, 2003||Aug 18, 2004||Oticon A/S||Device and method for detecting wind noise|
|EP2107826A1||Mar 31, 2008||Oct 7, 2009||Bernafon AG||A directional hearing aid system|
|EP2182739A1 *||Aug 20, 2009||May 5, 2010||Siemens Medical Instruments Pte. Ltd.||Adaptive microphone system for a hearing aid and accompanying operating method|
|EP2262285A1||Jun 2, 2009||Dec 15, 2010||Oticon A/S||A listening device providing enhanced localization cues, its use and a method|
|EP2306457A1||Aug 24, 2009||Apr 6, 2011||Oticon A/S||Automatic sound recognition based on binary time frequency units|
|EP2381700A1||Apr 20, 2010||Oct 26, 2011||Oticon A/S||Signal dereverberation using environment information|
|EP2439958A1||Oct 6, 2010||Apr 11, 2012||Oticon A/S||A method of determining parameters in an adaptive audio processing algorithm and an audio processing system|
|EP2463856A1||Dec 9, 2010||Jun 13, 2012||Oticon A/s||Method to reduce artifacts in algorithms with fast-varying gain|
|EP2503794A1||Mar 24, 2011||Sep 26, 2012||Oticon A/s||Audio processing device, system, use and method|
|EP2519032A1||Apr 26, 2011||Oct 31, 2012||Oticon A/s||A system comprising a portable electronic device with a time function|
|EP2528358A1||May 23, 2011||Nov 28, 2012||Oticon A/S||A method of identifying a wireless communication channel in a sound system|
|EP2541973A1||Jun 27, 2011||Jan 2, 2013||Oticon A/s||Feedback control in a listening device|
|EP2560410A1||Aug 15, 2011||Feb 20, 2013||Oticon A/s||Control of output modulation in a hearing instrument|
|EP2563044A1||Aug 23, 2011||Feb 27, 2013||Oticon A/s||A method, a listening device and a listening system for maximizing a better ear effect|
|EP2563045A1||Aug 23, 2011||Feb 27, 2013||Oticon A/s||A method and a binaural listening system for maximizing a better ear effect|
|EP2574082A1||Sep 20, 2011||Mar 27, 2013||Oticon A/S||Control of an adaptive feedback cancellation system based on probe signal injection|
|EP2584794A1||Oct 17, 2011||Apr 24, 2013||Oticon A/S||A listening system adapted for real-time communication providing spatial information in an audio stream|
|EP2613566A1||Jan 3, 2012||Jul 10, 2013||Oticon A/S||A listening device and a method of monitoring the fitting of an ear mould of a listening device|
|EP2613567A1||Jan 3, 2012||Jul 10, 2013||Oticon A/S||A method of improving a long term feedback path estimate in a listening device|
|WO2000030404A1 *||Nov 16, 1999||May 25, 2000||The Board Of Trustees Of The University Of Illinois||Binaural signal processing techniques|
|WO2000041436A1 *||Jan 5, 2000||Jul 13, 2000||Phonak Ag||Method for producing an electric signal or method for boosting acoustic signals from a preferred direction, transmitter and associated device|
|WO2001097558A2 *||Jun 5, 2001||Dec 20, 2001||Gn Resound Corporation||Fixed polar-pattern-based adaptive directionality systems|
|WO2001097558A3 *||Jun 5, 2001||Mar 28, 2002||Gn Resound Corp||Fixed polar-pattern-based adaptive directionality systems|
|WO2007106399A2||Mar 9, 2007||Sep 20, 2007||Mh Acoustics, Llc||Noise-reducing directional microphone array|
|WO2011027005A2||Dec 20, 2010||Mar 10, 2011||Phonak Ag||Method and system for speech enhancement in a room|
|WO2012010195A1||Jul 19, 2010||Jan 26, 2012||Advanced Bionics Ag||Hearing instrument and method of operating the same|
|WO2012010218A1||Jul 23, 2010||Jan 26, 2012||Phonak Ag||Hearing system and method for operating a hearing system|
|WO2014062152A1||Oct 15, 2012||Apr 24, 2014||Mh Acoustics, Llc||Noise-reducing directional microphone array|
|U.S. Classification||381/92, 381/94.7|
|International Classification||H04R3/00, H04R1/40|
|Cooperative Classification||H04R3/005, H04R2430/21, H04R1/406|
|European Classification||H04R3/00B, H04R1/40C|
|Nov 5, 1993||AS||Assignment|
Owner name: AMERICAN TELEPHONE AND TELEGRAPH COMPANY, NEW YORK
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:CEZANNE, JUERGEN;ELKO, GARY WAYNE;REEL/FRAME:006771/0815
Effective date: 19931104
|Jun 7, 1995||AS||Assignment|
Owner name: AT&T CORP., NEW YORK
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Owner name: CHASE MANHATTAN BANK, AS ADMINISTRATIVE AGENT, THE
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|Jun 26, 2003||REMI||Maintenance fee reminder mailed|
|May 31, 2007||FPAY||Fee payment|
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|Feb 17, 2009||RR||Request for reexamination filed|
Effective date: 20081224
|Feb 23, 2010||B1||Reexamination certificate first reexamination|
Free format text: THE PATENTABILITY OF CLAIMS 1-23 IS CONFIRMED.
|Apr 20, 2010||RR||Request for reexamination filed|
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|Apr 29, 2010||AS||Assignment|
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Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:AGERE SYSTEMS, INC.;REEL/FRAME:027464/0486
Effective date: 20111004
|Jul 31, 2012||RR||Request for reexamination filed|
Effective date: 20120615
|Jul 2, 2013||FPB2||Reexamination decision cancelled all claims (2nd reexamination)|